JPH0197065A - Facsimile equipment - Google Patents

Abstract

PURPOSE:To constitute the facsimile equipment of higher performance by providing half tone processing means of at least more than two, which can mutually compensate other faults and selecting them according to purposes so as to use them. CONSTITUTION:A binary processing circuit 2 which processes the binary original of black and white in an optimum method, a half tone processing circuit 3 by a dither processing, a half tone processing circuit 4 by an error diffusion method, a control part 5 which switches and controls the flow of data in case of need, and selection circuit parts 10 and 12 which the control part 5 switch are given. The selection circuits 10 and 12 select the connection of picture signals outputted from an original scanning part 1. When a transmission time is intended to be saved even if a picture quality is more or less deteriorated, the half tone processing circuit 3 is selected, and when the picture quality is considered as important even if the transmission time becomes longer, the half tone processing circuit 4 is selected. At the time of copying a half tone original, the processing circuit 4 by the error diffusion method is selected. When the original consists of only characters and the half tone processing is not necessary, the binary processing circuit 2 is selected.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is directed to facsimile IT! The present invention relates to iK, and particularly relates to a facsimile machine that has a plurality of halftone image signal processing means and can select the optimum halftone image signal processing means depending on the purpose.

BACKGROUND OF THE INVENTION Conventional facsimile machines generally consist of a color image signal processing circuit for black and white originals and a pseudo-halftone processing circuit using dither processing for halftone originals such as photographs. It is true. This dither processing circuit can be constructed with a relatively simple circuit, and the dithered image signal has the advantage of being able to efficiently compress data with simple preprocessing, so it is widely used. 7Aximi IJ device is used.

Problems to be Solved by the Invention On the other hand, despite the above-mentioned advantages, there are many complaints, especially regarding the image quality of dithered halftone originals.

The resolution decreases in proportion to the size of the dither matrix.

For manuscripts containing both photographs and text, the reproducibility of thin characters is inherently poor, and any attempt to improve this will deteriorate the reproducibility of the gradation of the photographic portion, making it difficult to achieve both.

It has the following disadvantages.

The present invention has been made in view of the above-mentioned conventional situation,
SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a new facsimile apparatus which makes it possible to overcome the above-mentioned disadvantages inherent in the prior art.

Means for Solving the Problems In order to achieve the above object, 1.7 axis IJ according to the present invention.
The apparatus is configured to include at least one halftone processing means that can compensate for the defects of each other, and a selective use means that selects and uses the plurality of halftone processing means according to the purpose. be done.

Embodiment Next, a preferred embodiment of the present invention will be specifically explained with reference to the drawings.

FIG. 1 is a block diagram showing one embodiment of the present invention.

Referring to FIG. 1, reference numeral l denotes a document scanning unit that scans a document to be transmitted or copied and converts the optical information into a digital electrical signal of a predetermined number of bits with a predetermined resolution. is a binary processing circuit that processes a black and white binary document in an optimal manner, J is a halftone processing circuit using dither processing (C), and l is a halftone processing circuit using an error diffusion method (C).
, j is a control unit that switches and controls the data flow as necessary; No. 1 is an image signal memory unit that stores nine-binary image signals processed by processing circuits 1, 3, and 2; An encoding and decoding unit performs data compression and expansion; t is a line control unit that controls transmission and reception over the line; and 9 is a printer unit that prints the contents of the image signal memory base.

IO and // and l indicate selection circuit units switched by the control unit 3, respectively.

Although the image signal processed by the dither halftone circuit J is not satisfied with the image quality, it is possible to compress the data.

Transmission and reception can be done in a relatively short time. In addition, the image signal subjected to halftone processing by the error diffusion method of the halftone processing circuit is
Although it has very high image quality, it is difficult to compress the data and requires a long time to transmit.

In this way, the halftone processing circuits 3 and q have advantages that compensate for each other's disadvantages.

In this second embodiment, the image signal output from the document scanning section is controlled by the control section in response to a selection instruction input by a person operating the apparatus to an input means (not shown). After that, the connection is selected in the selection cycle @10 as follows.

Even if the image quality is somewhat poor, if you want to save transmission time, select halftone processing circuit (C) using dither method J.

When image quality is important even if the transmission time is long, use II.
Select the halftone processing circuit (k) using the error diffusion method.

When copying a halftone original, select the processing circuit C using the error diffusion method.

If the original contains only characters and there is no need to perform halftone processing, select the binary processing circuit.

The nine-binary image signal processed by the processing circuit selected as described above is stored in the image signal memory 6.

The image signals stored in the image signal memory 6 are as follows.

In the case of transmission, the encoder and the decoder are connected, and in the case of copying, the printer is connected to each other under the control of the control unit S by a selection circuit /l.

When transmitting, the image signal stored in the single-picture signal memory 6 is compressed in data amount using a predetermined algorithm in the encoding and decoding circuit, and then transmitted from the single-line controller S. or,
In the case of reception, the image signal is sent to the image signal memory 6 through the reverse path.
is accumulated in

When copying, the image signal stored in the single image signal memory B is input to the printer t connected by the 6 selection circuit //, and the #J image is printed.

DETAILED DESCRIPTION OF THE INVENTION As described in detail, according to the present invention, a facsimile machine with higher performance can be constructed by having a plurality of halftone processing circuits having different characteristics and using these circuits depending on the purpose. can get.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of the present invention. l... Original scanning unit, K... Binary image signal processing unit, j1
．． . Halftone image signal processing section (1), d... Halftone image signal processing section),! ...control unit, 6...image signal memory unit, 7...encoding/decoding unit, t...line control unit, 9.
...Printer section. lO selection circuit, //...selection circuit, lco...selection circuit Patent applicant NEC Co., Ltd. Agent Patent attorney Yutabe Kumagai

Claims (1)

[Claims] A facsimile machine comprising at least two different halftone image signal processing means, and a selection means for selecting an optimal processing means from among the plurality of halftone image signal processing means depending on the purpose. Device.